class Solution {
public:
    vector<int> productExceptSelf(vector<int>& nums) {
        int n = nums.size();
        vector<int> f(n, 1), g(n, 1), ans(n);
        for (int i = 1; i < n; i++)
            f[i] = f[i - 1] * nums[i - 1];
        for (int i = n - 2; i > -1; i--)
            g[i] = g[i + 1] * nums[i + 1];
        for (int i = 0; i < n; i++)
            ans[i] = f[i] * g[i];
        return ans;
    }
};